The invention is directed to thermal cycling of material(s) and more particularly to thermal cycling of material(s) between an extremely large range of temperatures.
Vehicles for flights into space and satellites launched therefrom require the use of materials that can endure a large range of temperature change between the temperature on earth prior to launch, the temperature of outer space and the re-entry heat generated upon exposure to the earths atmosphere on return to earth. The selection of construction materials of these vehicles and satellites is especially critical primarily to insure the safety of humans which travel into space and return within the space vehicle, the extremely high cost encountered in the construction of the space craft and its payload and satellites are secondary economic considerations.
Although materials have been previously thermal cycle tested by placing them in evacuated or inert gas filled ovens where the temperature is elevated to a desired level and then removing the material from the oven and quenching the material into a super cooled liquid this method can be very dangerous and time consuming when many cycles from hot to cold and cold to hot is required and does not provide good temperature cycling control. In addition to the operators great exposure to danger especially when the cooling liquid is liquid hydrogen, a considerable amount of time is required and a considerable waste of super cooled liquid occurs due to boil off both of which are economically very expensive. When the material to be tested is of the type requiring heating in an inert atmosphere the material must be reduced in temperature prior to exposure to the atmosphere and the super cooled liquid. This requires considerable time for cycling and results in a test which does not truly cycle the material instantaneously between extreme heat and extreme cold within the temperature range required for the test.
Additional consideration must be directed to the safety of the personal operating the thermal cycling testing to prevent injury to them in the handling of volatile materials such as, liquid hydrogen, and the possibility of explosion.
There has not been an operator safe and successful means for thermal testing of material(s) between an extreme hot and cold temperature range until the emergence of the instant invention.